Method for producing a liquid guidance device

ABSTRACT

A method for producing a liquid-conducting device made of aluminum including a functional surface made of anodized aluminum. A surface of a strip- or layer-shaped aluminum sheet is provided with a masking during a masking phase for producing a processing on the surface of the aluminum sheet and in its structure. The aluminum sheet is processed in an electrolytic process for realizing a functional surface, which is provided with an aluminum oxide layer, on the processing surface, a body surface of the liquid-conducting device, which includes at least one processing surface or one functional surface, being sized as a component of the aluminum sheet during a sizing phase, the liquid-conducting device being separated from the strip- or layer-shaped aluminum sheet during a separating phase.

This application represents the U.S. national stage of International Patent Application PCT/EP2018/081232, filed on Nov. 14, 2018, which claims priority to German Patent Application No. 10 2017 222 238.7, filed Dec. 8, 2017, the disclosures of which are hereby incorporated by reference in their entirety.

The disclosure relates to a method for producing a liquid-conducting device made of aluminum sheet, in particular as a component of containers or container parts, the liquid-conducting device comprising a functional surface made of anodized aluminum.

The production of containers and container parts made of aluminum sheet whose surface is designed as a functional surface made of anodized aluminum has a multitude of uses. Aside from the aluminum oxide layer formed on the surface of the containers promoting effective oxidation protection, such surfaces have proven to be of value in particular as functional or adhesive surfaces which allow a particularly enduring paint coat on the container surface, for example.

For instance, DE 10 2013 214 321 A1 discloses a method in which containers produced by forming are immersed in an oxidation bath during an immersion process and the aluminum oxide layer is produced electrolytically on the container surface. In the known method, the entire outer surface of the container is provided with the aluminum oxide layer.

EP 2 885 227 B1 discloses a container which has a surface area made of anodized aluminum on a wall in contact with the liquid contained in the container in order to use the porous surface of the aluminum oxide structure for producing gas bubbles and for promoting gas bubble growth when a liquid oversaturated with nitrogen comes into contact with the aluminum oxide surface. The purpose is to use such a functional surface made from aluminum oxide for beverage cans containing beer in order to encourage foaming.

For yielding such a functional surface made of aluminum oxide, EP 2 885 227 B 1 proposes providing a plastic container with recesses on its inner side which are provided with anodically produced aluminum oxide.

Aside from the fact that filling beverages, such as in particular beer, which are generally consumed cold, in beverage cans made of aluminum sheet being preferred because the temperature conductibility of aluminum sheet is considerably better than that of plastic, consumers generally have reservations against beer filled in plastic beverage cans.

The object of the disclosure at hand is therefore to propose a method for producing a liquid-conducting device as well as the liquid-conducting device itself which enables the liquid to come into contact with a functional surface formed on the liquid-conducting device and which can be produced inexpensively.

In order to attain this object, the method according to the disclosure has the features of claim 1.

In the method according to the disclosure for producing a liquid-conducting device, which can be realized in particular as a component of containers or container parts, a functional surface made of anodized aluminum is realized on an aluminum sheet by providing a strip- or layer-shaped aluminum sheet with a masking during a masking phase for producing a processing surface defined in its position and structure; by processing the aluminum sheet in an electrolytic process during a processing phase for realizing a functional surface, which is provided with an aluminum oxide layer, on the processing surface; by sizing a body surface of the liquid-conducting device comprising at least one processing surface or functional surface as a component of the aluminum sheet during a sizing phase; and by separating the liquid-conducting device from the strip- or layer-shaped aluminum sheet during a separating phase.

In the method according to the disclosure, the position of a functional surface made of anodized aluminum on the surface of the liquid-conducting device is defined by means of a masking, which is applied to the aluminum sheet, as early as in a phase of production in which the material used for the liquid-conducting device, i.e., aluminum sheet, is still available in strips or layers, i.e., as a starting material to be processed, meaning a processing surface is defined as early as in this phase for subsequent subjection of the aluminum sheet to electrolysis, the anodic oxidization subsequently taking place on the processing surface for realizing the functional surface. Consequently the functional surface is realized on the processing surface.

Since this means that only the surface areas of the aluminum sheet which are to later form the actual functional surface have to be subjected to electrolysis, only a correspondingly reduced energy input is required for the anodizing process so that significant amounts of energy can be saved in comparison to conventional practice in which the entire surface is anodized.

Moreover, the method according to the disclosure enables generating the functional surface at a position exactly defined by the masking of the starting material so that not only effects which can be attained by the functional surface in the liquid, such as foaming the liquid, can be limited locally and in a defined manner but also surface areas which are not supposed to be affected by the functional surface in particular due to an intended aesthetic effect or a desired feel are excluded from anodization.

Furthermore, realizing the processing surfaces on a strip or layer level of the aluminum sheet enables a continuous or batch production when transforming the processing surfaces to functional surfaces.

If the aluminum sheet is strip-shaped, it is therefore possible to guide the aluminum sheet continuously through an electrolytic bath or to subject it to the electrolyte in a spraying process after the masking has been applied, for example as a varnish coat in a printing process. In a batch operation, the known immersion method can be used for transforming the processing surfaces to functional surfaces, for example.

The method according to the disclosure further has a sizing phase in which a body surface of the liquid-conducting device comprising at least one processing surface or functional surface is sized as a component of the aluminum sheet.

It is essential for all possible variations of the method that the processing surface, which is transformed to the functional surface by the electrolysis, is defined at a point in time after a previous masking at which the aluminum sheet is still strip- or layer-shaped.

Depending on the desired surface quality of the container inner wall, the masking can be realized as a permanent or a temporary masking.

The processing phase can be performed before or after the sizing phase, but, as previously indicated, definitely after the masking phase. It is particularly sensible for a processing phase to follow the sizing phase when the sizing phase is to serve not only for determining the outer contour of the processing-surface surroundings, i.e., a body surface of the liquid-conducting device to comprise the functional surface, but also for influencing the surface topography of the subsequently produced functional surface. Such a sizing can be performed using an embossing stamp, i.e., a forming tool.

In a preferred embodiment of the method, the sizing phase is performed at the same time as the separating phase so that the liquid-conducting device can be separated from the strip- or layer-shaped starting material in a bending and stamping procedure, for example, and the liquid-conducting device can be shaped in a shared work step.

If, according to a preferred embodiment, the separating phase is performed after the sizing phase, the body surface sized during the sizing phase, in particular by forming, can present merely a component or a partial area of the liquid-conducting device produced by being separated from the aluminum sheet.

If the separating phase is performed after the sizing phase, which is performed subsequently to the masking phase by forming a formed area, for example, and before the processing phase for forming the functional surface, the electrolysis for transforming the processing surfaces to the functional surfaces can also be performed on the container or the container part instead of on the strip or layer level.

The liquid-conducting device according to the disclosure has the features of claim 7.

According to the disclosure, the liquid-conducting device made of aluminum sheet has a functional surface made of anodized aluminum, the functional surface forming merely a partial surface of a body surface of the liquid-conducting device.

In a particularly simple embodiment, liquid-conducting devices according to the disclosure can be realized as stirring rods or a body around which the liquid must flow, the stirring rods or body having a functional surface on a carrier surface made of aluminum sheet, the functional surface inducing effects in the liquid caused by the surface of the functional surface upon contact with an oncoming liquid.

It is to be noted in general that the effect intended to be caused in the medium hitting the functional surface by the liquid-conducting device provided with the functional surface is not limited to a liquid contact medium as such. In fact, the functional surface can also induce effects in a powder or a different pourable dump material which comes into contact with the functional surface so that the term “liquid-conducting device” does not semantically restrict the patent application at hand to the use with only liquids but can also be interpreted as a “powder-conducting device” or even a “dump-material-conducting device”.

The functional surface can be realized asymmetric in particular for inducing special effects in a liquid coming into contact with the functional surface. For instance, when the functional surface is helical in shape, a vortex formation encouraged by the helical shape of the functional surface can enhance bubble nucleation in a beverage oversaturated with nitrogen, the bubble nucleation being induced or supported by the anodized aluminum surface.

Preferably the liquid-conducting device is produced by forming a sheet blank.

In a preferred embodiment, the liquid-conducting device is realized as a container part.

In another embodiment, the liquid-conducting device is realized as a component of a container part.

It is particularly preferable if the liquid-conducting device is realized as a container closing device disposed on a container lid.

In a particularly preferred embodiment, the liquid-conducting device is realized as a container, the functional surface being able to be realized on only an inner cup edge, for example.

In the following, one possibility of performing the method and of a container produced using this method are described in more detail by means of the drawing.

FIG. 1 is an isometric view of a beverage container;

FIG. 2 shows a container part realized as a container lid of the container shown in FIG. 1;

FIG. 3 is a schematic view of the method sequence for producing a container part of the container lid shown in FIG. 2;

FIG. 4 is an individual view from the bottom of a container part produced using the method shown in FIG. 3;

FIG. 5 is an isometric view of the container part shown in FIG. 4.

FIG. 1 shows a container 10 which is realized as a beverage can and comprises the following essential parts: a container pot 12 defining a container interior 11 and a container lid 13 sealing container pot 12.

Container lid 13 is shown in an open position in FIG. 2 and comprises a container closing device 14 provided with an opening tab 15 and a pouring protrusion 16 which forms a liquid-conducting device. Opening tab 15 comprises a pivoting axis 17 which is located in a pivot holder 19 formed in a lid bottom 18. On one side of pivot axis 17 is located an actuation end 20 which can be pivoted about pivot axis 17 by means of an opening movement 21 so that a push opener 22 of opening tab 15, which is formed opposite actuation end 20 on the other side of pivot axis 17, is pivoted against a closing piece (not illustrated) formed in lid bottom 18 and the closing piece is detached from a connection to surrounding lid bottom 18 by means of push opener 22 by destroying a predetermined breaking device 24 and is pivoted downward when continuing opening movement 21 so that a pouring protrusion 25 is formed in lid bottom 18.

As shown in FIG. 2, a functional surface 27, which has an anodically produced aluminum oxide layer on container closing device 14 formed from the aluminum sheet, is located on an underside 26 of the liquid-conducting device realized as pouring protrusion 16 in this instance. Functional surface 27 causes a pouring procedure to induce or enhance foaming when a beverage contained in container interior 11, e.g., beer, comes into contact with functional surface 27.

FIG. 3 shows the production method for producing container closing device 14 shown in FIGS. 4 and 5.

As FIG. 3 shows, production of container closing device 14 starts with a strip-shaped aluminum sheet 32 in this instance, which consecutively passes through several processing stations, namely a masking station 28, an electrolysis station 29, a forming station 30 and a separation station 31. Depending on the configuration of the processing stations, the infeed of strip-shaped aluminum sheet 32 can take place in a continuous or clocked manner.

With this shown exemplary embodiment, a masking 34 is applied to the surface of aluminum sheet 32 with a masking lacquer at masking station 28, the masking lacquer being able to be applied in such a manner using a printing mechanism, for example, that a plurality of processing surfaces 33 are defined preferably in a matrix array on the surface of aluminum sheet 32 with regard to their size, their position and in particular their structure.

The exemplary illustration of FIG. 3 notwithstanding, processing surfaces 33 therefore do not have to be designed as a contiguous surface but can rather be provided with a masking grid formed by the masking lacquer.

In a processing phase following the previously described masking phase, aluminum sheet 32 passes through electrolysis station 29 at which an electrolyte is applied to the surface of aluminum sheet 32 by spraying, for example; due to masking 34, a surface reaction for forming an anodized aluminum oxide surface as a functional surface 27 takes place only in the area of processing surfaces 33 not covered by masking 34.

Subsequently, aluminum sheet 32 passes through forming station 30 for performing a sizing phase during which body surfaces 37, which are realized as bowl-shaped recesses in the present instance, are sized by realizing formed areas 36 which are produced using an embossing or deep-drawing procedure.

Subsequently, liquid-conducting devices 14, which comprise body surfaces 37 and are realized as container closing devices as shown in FIGS. 4 and 5 in this instance, are separated in the shown method variation at a separation station 31 during a separating phase of the method.

A synopsis of FIGS. 4 and 5 clearly shows that on the container closing device 14 separated from aluminum sheet 32, functional surface 27 is realized on a bottom 38 of body surfaces 37 designed as bowl-shaped recesses, bottom 38 forming underside 26 (FIG. 2) of pouring protrusion 16. Opening tab 15 of container closing device 14 shown in FIGS. 1 and 2 is formed by a protrusion 39 separated from aluminum sheet 32 in conjunction with formed area 36 during the separating phase.

As a synopsis of FIGS. 4 and 5 clearly shows, a ridge 40 framing functional surface 27 is formed on underside 26 of container closing device 14, which is produced according to the production method shown in FIG. 3, in the area of the pouring protrusion 16 formed by the bowl-shaped recesses 37, web 40 abutting against lid bottom 18 of a closed container 10 so that ridge 40 enables realizing a hermetically sealed space when lid bottom 18 is closed, in particular if ridge 40 is provided with an adhesive sealing material (not further illustrated), such as in particular silicone, functional surface 27 being shielded from environmental influences and contact to the liquid in the sealed space until the opening procedure described in the introduction of the description is performed and a beverage contained in container interior 11 and functional surface 27 come into contact with each other during the pouring procedure. 

1. A method for producing a liquid-conducting device made of aluminum sheet, in particular as a component of containers or container parts, the liquid-conducting device comprising a functional surface made of anodized aluminum, wherein a surface of a strip- or layer-shaped aluminum sheet is provided with a masking during a masking phase for producing a processing surface defined in its position on the surface of the aluminum sheet and in its structure, the aluminum sheet being processed during a processing phase in an electrolytic process for realizing a functional surface, which is provided with an aluminum oxide layer, on the processing surface, a body surface of the liquid-conducting device which comprises at least one processing surface or one functional surface, being sized as a component of the aluminum sheet during a sizing phase, the liquid-conducting device being separated from the strip- or layer-shaped aluminum sheet during a separating phase.
 2. The method according to claim 1, wherein the masking is realized as a permanent or temporary masking.
 3. The method claim 1, wherein the processing phase is performed before or after the sizing phase.
 4. The method claim 1, wherein the sizing phase is performed simultaneously with the separating phase.
 5. The method claim 1, wherein the body surface is sized by realizing a formed area comprising the processing surface or the functional surface.
 6. The method according to claim 1, wherein the separating phase is performed after the sizing phase.
 7. The method according to claim 6, wherein the separating phase is performed after the sizing phase and before the processing phase.
 8. A liquid-conducting device made of aluminum sheet comprising a functional surface made of anodized aluminum, the functional surface forming merely a partial surface of a body surface of the liquid-conducting device.
 9. The liquid-conducting device according to claim 8, wherein the functional surface is asymmetric.
 10. The liquid-conducting device according to claim 8, wherein the liquid-conducting device is produced by forming a sheet blank.
 11. The liquid-conducting device according to claim 8, wherein the liquid-conducting device is realized as a container part.
 12. The liquid-conducting device according to claim 8, wherein the liquid-conducting device (14) forms a component of a container part.
 13. The liquid-conducting device according to claim 12, wherein the liquid-conducting device is realized as a container closing device disposed on a container lid.
 14. The liquid-conducting device according to claim 8, being realized as a container. 